In the textile industry it is common to treat fibers with a sizing composition prior to the weaving process. In the sizing treatment, the size composition adheres to and binds together fibers thereby lubricating and strengthening the fibers. Lubricated fibers allow for faster speeds to be used in the subsequent weaving operation without building up as much static electricity as compared to untreated fibers, and strengthened fibers are more resistant to abrasion and breaking during the weaving operation.
Many types of polymers have been used as sizing agents in the sizing of textiles. These sizing agents include, for instance, starch, starch derivatives, gelatin, polyvinyl alcohol, acrylics, alkali metal salts of maleic anhydride/styrene copolymers, and sulfonic acid metal salt derivatives of polyesters. The disadvantages associated with the use of such sizing agents are that they form brittle hard films on fibers and thus require the addition of waxy type lubricants in order to provide lubrication during sizing. These waxy type lubricants are typically oils and fats which are difficult to remove with water during desizing because they are hydrophobic. Additionally, such sizing agents are characterized by poor soil release properties and thus do not effectively remove the natural and synthetic waxes from the fibers during desizing or scouring. Furthermore, such sizing agents, in particular starch and polyvinyl alcohol, are difficult to resolubilize due to hydrogen bonding even in an alkaline medium and thus are difficult to remove during desizing.